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Re: [RFC] perf probe: Fix module probe issue if no dwarf support

From Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Newsgroups linux.kernel
Subject Re: [RFC] perf probe: Fix module probe issue if no dwarf support
Date 2016-04-26 11:10 +0200
Message-ID <rs7aj-4SP-17@gated-at.bofh.it> (permalink)
References <rrM5Q-4ay-5@gated-at.bofh.it> <rrM5Q-4ay-3@gated-at.bofh.it> <rrWeR-49v-9@gated-at.bofh.it>
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On Tuesday 26 April 2016 02:59 AM, Masami Hiramatsu wrote:
> On Mon, 25 Apr 2016 16:08:28 +0530
> Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> wrote:
>
>> Perf is not able to register probe in kernel module when dwarf supprt
>> is not there(and so it goes for symtab). Perf passes full path of
>> module where only module name is required which is causing the problem.
>> This patch fixes this issue.
>>
>> Before applying patch:
>>
>>    $ dpkg -s libdw-dev
>>      dpkg-query: package 'libdw-dev' is not installed ...
>>
>>    $ ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
>>      Added new event:
>>        probe:foo_show (on foo_show in /linux/samples/kobject/kobject-example.ko)
>>
>>      You can now use it in all perf tools, such as:
>>
>>    perf record -e probe:foo_show -aR sleep 1
>>
>>    $ cat /sys/kernel/debug/tracing/kprobe_events
>>      p:probe/foo_show /linux/samples/kobject/kobject-example.ko:foo_show
>>
>> After applying patch:
>>
>>    $ ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
>>      Added new event:
>>        probe:foo_show (on foo_show in kobject_example)
>>
>>      You can now use it in all perf tools, such as:
>>
>>    perf record -e probe:foo_show -aR sleep 1
>>
>>    $ cat /sys/kernel/debug/tracing/kprobe_events
>>      p:probe/foo_show kobject_example:foo_show
>>
> Looks good to me :)
> However, it seems that this patch depends on your previous patch
> ("perf probe: Fix offline module name missmatch issue")
> In that case, could you make these a series of patches?
>
> Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Thanks Masami,

I've sent v2 with changes you suggested. Please review it.

Regards,
Ravi

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[RFC] perf probe: Fix module probe issue if no dwarf support Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> - 2016-04-25 12:40 +0200
  Re: [RFC] perf probe: Fix module probe issue if no dwarf support Masami Hiramatsu <mhiramat@kernel.org> - 2016-04-25 23:30 +0200
    Re: [RFC] perf probe: Fix module probe issue if no dwarf support Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> - 2016-04-26 11:10 +0200

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